SAXS structural characterization of a liposome-based drug product


The application of liposomes for targeted drug delivery has had a major impact in many biomedical areas. Liposomes are attractive as a delivery system due to their flexibility in their physicochemical and biophysical properties.

Liposomal drug delivery systems are very effective for targetted delivery of small-molecule drugs, vaccines and genes. The physical characterization of drug-loaded liposomes becomes important and is often required by regulatory to obtain the marketing autorization for the drug product.

At DANNALAB, with the use of Small Angle X-Ray Scattering (SAXS), we are capable of reconstructing the structure of a liposome carrier, either alone- or loaded with a drug.

Below, Figure 1 presents an example showing the model we use for the characterization of liposomal doxorubicin.

SAXS liposomal doxorubicin

Parameters of the model are refined to achieve the best fit between the measured differential SAXS pattern and the pattern calculated from a model.

For the model presented in Figure 1 we obtain information about the thickness and density of the lipid bi-layers, the PEG corona and the dimensions of a loaded nanocrystalline drug.